There has always been a desire to highlight information on pages in order to show emphasis. Thus, the major market for highlight markers. Marker emphasis is simple and visual in nature. In the legal industry, for example, highlighted text from legal briefs is used to form new documents. An attorney may mark a document with colors demonstrating the “pros” and “cons” of a particular case for both the defendant and prosecution. Administration support is typically responsible for transcribing the highlighted portions of the document to new documents. This is a very time consuming effort.
Often, it is desirable to differentiate between regions of a document which have been “highlighted” with, for example, a highlighter pen from regions of a document which have not been highlighted. The term “highlighted” it is intended to mean herein that first marks in a document have been differentiated from remaining marks of the document by a region which has a substantially different gray scale than the background or marks of the original document. Such marks can be made, for example, by way of well known “Hi-Liter” pens, “Major Accent” pens, and other pens which produce bright but relatively transparent colors.
A variety of methods have been proposed for the detection of highlighted regions in a document. For example, the use of a color scanner has been proposed to detect regions of a document, which has been highlighted in a color different than the remainder of the document. Other processing methods utilize detection of an image, which may include shadow, mid-tone, and bright portions. The mid-tone portion may be screened with a low frequency screen to convert the image into a binary form. While meeting with some success, prior methods of detecting highlighted regions have encountered certain limitations.
Based on the foregoing it is believed that a need exists for improved image processing methods and systems, and more specifically to techniques for automatically discriminating between and extracting regions of a document which have been highlighted and regions of a document which have not been highlighted. It is believed that the implementation of such a method and system can reduce additional time and effort spent in extraction.